Gebäude 21, 1. OG
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Current animal welfare legislation (BGBL. I., 1986, 1319) stipulates that when a decision on the indispensability of animal experiments is to be made, the question of whether the purpose can be fulfilled using other methods or procedures is to be examined. Starting from there, this study had the task of making observations on the validity and validation of methods that realise the "3R" - replacement, reduction, refinement - from RUSSEL and BURCH (1959).Introductory theoretical considerations are concerned with methods of biomedical sciences and examination of methods in general. Particular importance is attached to the term of the object of a method as the object of the study to be carried out. This object, e.g. an organ preparation, causally determines the methods of its study.Various definitions of the validity of a method in literature and also statistical examination procedures which are used to assess the suitability and performance of methods are presented.The term of the validity of a method is already defined as the validity of the results of an empirical research procedure. For this two variables, sensitivity and specifity, must bedetermined.Validation is to be understood as a procedure by which the scientific validity of a method, and its ability to answer a specific question in place of an animal experiment previously used, is examined.There are already validation concepts for the examination of alternative methods in toxicology, especially to examine the acute irritation effect on the mucous membranes of chemicals instead of the DRAIZE test. These validation concepts are proposed as a model for the validation of other alternative methods in toxicology and, with consideration to methodical pecularities, for the methods in other fields.A written survey in scientific institutions, which in the formulation of its selective questions was orientated to a large extent to the validation concepts described in literature, made it possible to record alternative methods and qualitative data on their state of development. The data determined was presented in tables and discussed.It was shown that each method is to e understood as an individual case. The heterogenous character of the various methodical forms of procedure, which are each tailored to the concrete situation in which they are applied, rules out the possibility of, by referring to method studies, stating explicitly formulated procedural rules or even a general methodology, which the scientist would merely need to use as akind of recipe in order o gain answers to his questions. Systematic method studies have the task of establishing whether methodical forms of procedure fulfil given criteria. The examination of alternative methods must be understood in this sense.The validity of an alternative method always consists of:1. its scientific validity for the purposes of answering aquestion defined and2. its validity with regard to the realisation of one of the3R with reference to a conventionally used animalexperiment ("3R-quality").The following are general criteria for the validity of alternative methods:- the plausibility of the method in answering a question, - the specifity and sensitivity of a method, - the method report"s suitability for standardisation, - the method"s suitability for reception and comparison,- an animal experiment previously used for the examination ofa task or to answer a question is replaced by applying analternative method and/or the degree of stress to which theanimal is exposed (pain, suffering, harm) is reduced and - the successful practical application of the method.The examination of validity (validation) takes place gradually. A selective development of the method under examination takes place simultaneously until its practical application for the purposes of the 3R.How he validation of a method proceeds in detail must be stipulated for each method under examination.For this, expert knowledge both of the method under examination as well as of the method to be replaced or changed for the purposes of the 3R is required.The adaption of FRAIZER"s (1987, 1989) idea of the "Gold Standard" is recommended as a basis of comparison for the alternative methods under examination. "Gold Standard" refers to the data that has already been determined for a certain question in an ideal case in the species concerned or in an animal experiment and with which the data of the method under examination can be compared. The "Gold Standard" provides the reference data for the examination of the "3R-quality" of a method as opposed to the conventionally applied animal experiment method.The methods recorded and the information on their state of development are the basis for a documentation of methods, whose data structure has been proposed. Work has already started on the compilation of this documentation in the Centre for the Recording and Assessment of Alternative Methods - ZEBET - at the Bundesgesundheitsamt (BGA), Berlin. This documentation will make a contribution to the practical realisation of animal welfare legislation in an important sector. The methods documentation currently being compiled makes it increasingly possible for ZEBET to provide information on alternative methods and their state of development, to recommend methods ready for application for administrative implementation and to support the development and examination of methods in corresponding research plans.